There has been a constantly growing bandwidth demand of users along with the development of network technologies, and an increasing number of video and other applications. Existing network devices can only access the Internet via single network interface at a time, so the network bandwidth may be limited by network deployment by a serving operator and the current number of users in this scenario. Although the network devices of the users are provided with a plurality of network interfaces via which they can access different types of networks, including wired networks, wireless networks, cellular data networks, etc., data on a virtual card can only be transferred on a default network device, so the users can not access the Internet over these networks concurrently.
The technology of layer 2 Tunneling Protocol (L2TP) is a widely applied Virtual Private Network (VPN) technology in which a device with a plurality of network interfaces can set up a tunnel with an L2TP server through an L2TP client so that the device can access the Internet over a proxy VPN of the server. In the prior art, the L2TP enabled device with a plurality of network interfaces sets up virtual links over a plurality of physical links over which data are transmitted, and generates respective virtual network cards for the virtual links corresponding to the respective network interfaces, where data on the virtual network card are transmitted over the physical link corresponding to the interface of a default route thereof. In the prior art, although the device is provided with a plurality of network interfaces, there is only one default route, so that the data can not be transmitted concurrently over the plurality of physical links corresponding to the plurality of network interfaces, thus resulting in a waste of the resources in the network with a plurality of links.
Thus in the prior art, the device with a plurality of network interfaces can only transmit the data over the physical link corresponding to the single network interface in the default route, so that the data can not be transmitted concurrently over the plurality of physical links corresponding to the device with a plurality of network interfaces, thus resulting in a waste of the resources in the network with a plurality of links.